This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a genotype-based recall study to contrast individuals discordant for specific single nucleotide polymorphism (SNP) in the gene for transcription factor 7-like 2 (TCF7L2). TCF7L2 is a susceptibility gene for type 2 diabetes that appers to affect pancreatic beta-cell function.This study will recall pervious participants of the BetaGene study who are discordant for the SNP rs 12255372 and repeat the series of phenotyping that was performed in the original BetaGene study visit. The purpose of this study it to contrast between the two genotypes groups and to also assess differences in GLP1 concentrations during the oral glucose tolerance test (OGTT). The second goal is to assess whether the temporal change in the phenotypes (current phenotype value - phenotype value at original BeteGene visit ) is different between the two genotypes and whether these changes are altered by body fat. Non-diabetic individuals who previously participated in the BeteGene study are discordant for rs12255372 genotype will be eligible for this study. Paticipants will undergo two GCRC visits. The first visit will consist of physical examination and OGTT. The second visit will consist of an intravenous glucose tolerance test and a DEXA scan. . Fasting blood will be collected for DNA, RNA, and lipids.